Coral Reef Diagnostics

Dilmunia Rock (Bahrain)

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05
Coral Health Index: TBD
Photo: Anderson Mayfield/Coral Reef Diagnostics
Country
Bahrain
Survey date(s)
2023-09-23
Coordinates
26.2850, 50.6350
Coral cover
11%
Computer vision analysis of images · details below
Observations
bleaching
Heat stress
Today’s heat load
34.7°C10.3°C-weeks
11 Sep 2026 · Alert Level 2
5-year thermal stress load
5-year mean max. degree heating weeks (DHW)
9.9°C-weeksi
2021–2025
NOAA Coral Reef Watch — Bahrain virtual station
i 5-year mean max. DHW is the mean of the annual maximum DHWs over the five complete years named above, not conditions today.
More infoBahrain (NOAA CRW virtual station) · Arabian (Persian) Gulf ecoregion mean=9.8°C-heating weeks
Photographs
21
Site summary
Read this summary in:

Dilmunia Rock is a shallow, sheltered site less than 2 km off Bahrain, with a rocky ledge near 5 m dropping to sand, known locally for its fish life and Bahrain's characteristic nudibranchs. Its corals live in one of the hottest reef environments on Earth, where repeated severe bleaching has hit Gulf reefs over the past three decades.

One other CRD dive site within 5 km shown in orange — click a marker to open its page.

9 of these 21 photographs are shown beside the text that discusses them under "Site description" below.

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Photo credit & attribution

Site description

Setting

Dilmunia Rock is a shallow site less than 2 km off Bahrain in the Arabian Gulf (26.285 N, 50.635 E). Published site descriptions - not observations of Anderson's - place it between roughly 5 and 10 m, with a rocky ledge near 5 m giving way to a sand bottom below (e.g., Image 4, Image 6, Image 10, Image 11, Image 12).

4Image 46Image 610Image 1011Image 1112Image 12

Coral cover

No coral-cover figure has been extracted, and there is no personal or nearby independent survey data for the site at all. A cover figure will be added only if transect data or a computer vision pass on Anderson's own photographs becomes available.

Stressors

As regional context rather than an account of this reef: Arabian Gulf corals live in one of the most thermally extreme reef environments on Earth, routinely exceeding summer temperatures lethal to conspecifics elsewhere, and Gulf reefs have suffered repeated severe bleaching and mortality over the past three decades. The satellite-derived five-year mean annual maximum heat stress for the grid cell is 9.9 degree heating weeks. No crown-of-thorns starfish (COTS) or other corallivores evident.

Comparisons with other data

Also on record for this site: It's known locally for its fish life and for Bahrain's characteristic nudibranchs, and its shallow, sheltered profile makes it suitable for both beginner and experienced divers (e.g., Image 5, Image 9, Image 13, Image 14).

5Image 59Image 913Image 1314Image 14

Dive record

Unlike most pins in this set it carries a real logged date: Anderson dived it on 23 September 2023.

Other notes

Sixteen photographs from that dive are published here.

Coral cover: method notes

As of September 2026 no computer-vision method estimates coral cover accurately on new images, so treat this as indicative rather than a measurement; it is revised as the methods improve.

Data & links

All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics.

© Coral Reef Diagnostics.